Just returned from an excellent 2-week Caribbean cruise on the Britannia.
We have cruised about 8 times before (including the Caribbean), and been on the Azura and Ventura before, but not the Britannia.
Firstly, the ship. We liked it and thought it an upgrade on Azura and Ventura (which we also like). However, we do see how some people say it is beige and boring, and this is especially so if you have been on new ships in other fleets e.g. Anthem of the Seas.
1.5 great days - one spent at the Boatyard in Carlisle Bay and the other afternoon in Bridgetown
Fantastic day on the beach at Reflexions Beach Bar
The only thing to do in Grenada is take the water taxi to Grand Anse.....
Plenty of taxis offering reasonable island tours and we went to the Dockyard and Shirley Heights. Worth the effort.